Urethane (meth)acrylate polymers, particularly polydiene urethane (meth)acrylates (oligomeric/polymeric substances containing polydiene segments, urethane linkages and (meth)acrylate functional groups), have broad applications in laminating adhesives and pressure sensitive adhesives, due to their low dielectric constant, excellent adhesion properties and moisture and oxygen barrier properties. However, the hydrophobic nature of these materials makes them difficult to formulate with other ingredients (e.g., tackifiers, acrylate monomers, photoinitiators, etc.), which limits their applications. The resins are also typically cloudy, which limits their uses in adhesives that are intended to be optically clear.
Examples of curable urethane (meth)acrylate polymer compositions include those described in U.S. Pat. Nos. 7,932,302; 7,192,688; 4,587,201; 4,031,066 and U.S. Publication No. 2007/0179254.